In a conventional endoscopic apparatus of this kind, in particular, in the case of a color electronic endoscopic apparatus of a simultaneously operating system, ununiform components are added to a converted output of a charge coupled device (CCD) by ununiformity of the optical characteristics due to light source, light guide fiber, lens, a combination thereof, or ununiformity of the spectral transmission characteristics of a color filter attached to the entire surface of the CCD, and the spectral sensitivity characteristics of the CCD, thereby deteriorating the reproducibility of the color. To solve this problem, the conventional apparatus has a signal processing circuit disposed in an apparatus's body separated from a scope and adjusting the color in order to remove the adverse effects due to the ununiform components.
A color electronic endoscopic apparatus of a field sequential system has no color filter attached to a front surface of the CCD, but has three color filters disposed on a light source side so that it is possible to generate ununiformity. Accordingly, even when the field sequential system is used, a signal processing circuit for adjusting the color is disposed in the apparatus's body separated from the scope, as well as in the case of the above simultaneously operating system.
However, since the ununiformity of the optical characteristics of respective scopes to be exchanged are respectively different from each other, the color must be adjusted by the signal processing circuit every time when a new scope is attached to the apparatus's body and is used.
In the conventional electronic endoscopic apparatus of this kind, after the scope is attached to the apparatus's body, the color must be adjusted by the signal processing circuit to remove the adverse effects due to the ununiformity, while examining the situations of the ununiformity of the optical characteristics caused by the scope itself. Accordingly, the adjustment of the color is complicated, and it often takes a long time to adjust the color so as to have a high color reproducibility.